The present invention relates to a device for storing a plurality of developing units used in a copying machine, a printer, or the like.
Some image forming apparatuses of this type comprise a plurality of developing units, and switch these developing units by a rotary mechanism.
Another apparatus is proposed wherein a plurality of developing units are equipped in a storage device outside a main body. In this case, a moving operation is required to replace a developing unit inside the main body with a developing unit inside the storage device, or to move a developing unit inside the storage device into the main body.
In order to perform the above moving operation, the developing units must be moved in two directions in the storage device. During movement of a developing unit in one direction, a moving mechanism for the other direction may be operated, and as a result, the developing unit may be stopped at an abnormal position or the storage device or the developing unit may be broken by forcible movement.
In order to perform the above moving operation, a storage case for storing a developing unit is moved inside the storage device, and its storage portion must be precisely stopped at a developing unit taking out/in portion facing a developing unit taking out/in port of the main body.
However, a load acting on a mechanism for moving the storage case varies depending on the number of developing units stored in the developing unit storage device. If control is made in correspondence with a maximum number of developing units, when the number of developing units is small, stopping precision of the moving mechanism is impaired. If the moving mechanism is modified in order to improve the stopping precision, the mechanism becomes complicated and expensive.